Gas discharge tube



May 19, 1953 J. D. coBlNE GAS DISCHARGE TUBE Filed Dec. 1o, 1945/NVENTOR JAMES D. COB/NE J N w T T A TIME T/ME

W .M M

OUTPUT UW@ F/G- 2 F/Gf/ AAAAAAAAA Patented May 19, 1953 GAS DISCHARGETUBE James D. Cobine, Schenectady, N.-Y., assigner to the United Statesof America as represented by the Secretary of War Application December10, 1945, Serial No. 634,090

This invention relates generally to electrical apparatus and moreparticularly to a random pulse generator utilizing a gas discharge tubeand a magnetic iield.

While itji's generally appreciated `that a lga-S discharge tube may beutilizedas a random noise generator and as a pulse generator, it is notcommon knowledge that'a gas discharge tube may be used to provide arandom noise voltage, reinforced by random noise pulses, by theapplication of a magnetic field to the gas discharge occurring withinsuch a tube. y

It is an object of this invention to provide a noise generator whoseoutput consists of ran- Fig. 3 is a graph showing the probable processby which the random relaxation pulses are developed and strategic pointson the graph have been designated by the letters A, B, and C,respectively, to promote clarity in the following discussion of theoperation of this invention.

5 claims. (o1. 315-236) the tube.

A 'gas discharge tube such as a type 6D4. connected in a circuit asshown in Fig. 1, is arranged at the center of a gap between two magn'etpole faces as shown in Fig. 2, with the magnetic eld transverse to thelongitudinal axis of Such a device having the values of capacitor I I,plate resistor I2, the applied directcurrent potential B-{, and the fluxdensity of the transverse magnetic iield, all properly adjusted'wi1l`operate in such a fashion that they:v

output pulses consist of noise reinformed by random pulses. The voltageoutput of this random pulse generator system will be substantiallyconstant over a band of frequencies from dom noise voltages and randompulses. Such 25 cycles per second to at least 100 kc. an Output Voltageis accomplished by utilizingr A typical circuit such as illustrated inFig. 1 a conventional sweep circuit including a gas diS- might use avalue of capacitance of 0.004 mfd., charge tube and a resistor andcapacitor coma resistance of 48,000 ohms, and a source of div binationwith the sas discharge tube subjected rect current I4, applied to thetwo electromagtothe influence of a magnetic iield. 2o nets i3, I3 ofFig. l, to produce a magnetic field A random noise voltage and randompulse 0f approximatdy 370 gangs, generator are useful for many purposes,one 0f The curves shown in Fig. 3 show the probable which is to test theresponse of a receiver t0 process by which the random relaxation pulsesnoise. are developed. The capacitor II causes suf- Other objects,features, and advantages of this cient instability at the instant of arandom posinvention will suggest themselves to those skilled itive noisepulse, at a time corresponding to point in the art and will becomeapparent from the A, when the current is transferred from the arefollowing description of the invention taken in in tube I0 to thecapacitor I I, to cause extincconnection with the accompanying drawingsin tion of the arc in tube I0. At the extinction of which: the arc,corresponding to time B, the voltage Fig- 1 iS a Schematic diagram 0f aCircuit utiacross capacitor II increases during the time lizing theprinciples of this invention; interval B-C as required by the appliedvoltage Fig. 2 is an elevation showing an assembly in- B-I- and the Rf-Ctime constant of capacitor II corporating a gas discharge tube and twoelecand resistor l2,

tromagnets; and The effect of the magnetic field is to delay the Fis- 3iS a graph Showing the relationship 0f re-ignition of the are in tube Iu until a relatime versus Output voltage, condenser current, tively highvoltage is again developed across caand tube current of the circuitshown in Fig. 1. pacitor lI which then discharges to the arc volt-Refelrng 110W t0 Fig. 1, a gas discharge tube age and conditions remainnormal until another I0 is shunted by a capacitor II, and across the 4ohigh positive noise pulse appears. combination a source ofdirect-current potential While there has been here described what is isapplied througharesistor I2. at present considered to be the preferredem- Fig, 2 shows a physical arrangement of gas bodiment of theinvention, it will be obvious to discharge tube l0 Centered betWeen tWOeleCtIO- those Skilled in the ari', that Various changes magnets f3, |3-COIlCeI'ning the physical aI- 45 and modifications may be made thereinWithout rangement of the magnetic field with respect to departing fromthe scope of the invention the tube, it should be noted that themagnetic What is claimed is: eld is transverse to the longitudinal axisof the 1. A noise generator, comprising a normally tube, which, it willbe understood, is such as t0 conducting gas discharge tube having ananode effect a deection of the electron flow. and a cathode, a source ofpositive potential,

resistance means electrically connecting said anode to said source ofpotential, capacitor means electrically connecting said anode to saidcathode and means for applying a constant magnetic field transverse tothe longitudinal axis of said tube whereby the output of said tube con-3 s'ists substantially of random noise and random pulses.

2. A random pulse and noise signal generator comprising a normallyconducting electron tube relaxation oscillator circuit which is in anonoscillatory state, said electron tube having an electron current owpath therein,l and a source for a constant magnetic eid positioned withrespect to said tube for said field to deflect said electron currentflow path.

3. A random pulse and noise signal generator, comprising a saw-toothpulse oscillator circuit` including a gaseous discharge device shuntedby a storage condenser, being in a normal state of conductivity andhaving irregularly occurring periods of non-conductivity,4 said devicehaving a space current flow path therein, and means for eiecting a delayin the reestablishment of4 con ductivity of said device, including asource for a.k constant magnetic, eld. positioned for at least onecomponent o said eld. to eiect a deiiection of, said electron currentflow path.

4. A, pulsing system, comprising a gaseous electron discharge device,havingA a space cur- )IEP-f3r Path therein, a resistance in series withSaid device for connection therewith, across a source of. directpotential, said device being normall7 conductive., a storage condenserin shunt with. Said device, and a continually operative electromagnethaving its pole faces positioned to Drovide a constant magnetic eldhaving at least one component transverse to said space current path.

5. A noise generator comprising a gaseous electron discharge devicehaving a space current path therein, a resistance in series with saiddevice for connection therewith across a source of direct potential,said device being normally conductive, a storage condenser in shunt withsaid device, and a continually operative electromagnet having its polefaces positioned to Drovide a constant magnetic iield acting to deectthe: 110Wy of space current, said normally conductive device, beingintermittently rendered noncondnctive due to random noise pulses of anamplitude greater than a given amplitude, whereby a charging of saidcondenser occurs, said magnetic field acting to delay thereestablishment of the state of conductivity' of said device.

JAMES D. COBINE.

References' Cited in thev 111e Of this' patent UNITED STATES PATENTSNumber Name Date 2,180,815 Meier Nov. 21, 939 2,269,338 Edgerton Jan. 6,1942 2,375,130 Perrin et al May 1, 1945 30 2,416,307 Grieg Feb. 25, 1947

